Reducing-valve.



No. 722,355. PATENTED MAR. 10, 1903. P. E. GAIN.

REDUGIN Gr VALVE.

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N0 MODEL.

PATRICK E. OAIN, OF BOSTON, MASSACHUSETTS.

REDUCING-VALVE.

SPECIFICATION forming part of Letters Patent N o. 722,355, dated March 10, 1903.

Application tiled February 14, 1902. Serial No. 94,075. (No model.)

VT0 all whom it may concern:

Be it known that I, PATRICK E. GAIN, of Bost-on, in the county of Suffolk and State of Massachusetts, have invented a new and useful Reducing-Valve, of which the following is a specification.

My invention is a reducing-valve with two piston-valves, which control the iiow of steam (or other liuid or liquid under pressure) from inlet to outlet and which are automatically controlled through a valve operated by a diaphragin and its spring, as the low pressure varies above or below that desired, as will be clearly understood by reference to the accompanying drawings, in which- Figure l is a diametrical axial section of the preferred form of my valve. Fig. 2 is a sectional view showing the pistons in another position. Fig. 3 is like Fig. 2, except that the pistons are in a third position.

The pistons D and D' are between the inlet B and outlet B', and when my valve is'not under steam these pistons are in the positions shown in Fig. l; but when steam is let on it flows freely past the neck of piston D and under piston D', thereby lifting piston D' and flowing freely past the neck of that piston and through the outlet B' (see Fig. 2) until the pressure in outlet B' reaches the desired amount. As outlet B' is connected by passage b to one side of diaphragm ci, that diaphragm will be moved against its spring a' as soon as the pressure in outlet B' exceeds the amount desired and that motion of diaphragm a allows valve a2 to be moved away from its seat by the small spring under valve c2, when the low-pressure duid will tlow through passage b' into the cylinder-0f piston D above the upper end of piston D and move piston D against the force of its spring CZ to the position shown in Fig. 3, thus cutting off the supply of steam from inlet B. This almost instantly reduces the pressure in the outlet B' and between the pistons D and D', so that piston D.' moves back by its own weight and the access of fluid through passage b2 to the position shown in Fig. 3, and both pis' tons act to cut off the iiow of steam from inlet B to outlet B', and pressure in outlet B' and its connectionssoon falls below the desired amount, whereupon diaphragm o, is moved back by its spring ct', carrying valve c2 back on its seat as and stopping the flow oflow-pressure fluid through passage b' into the cylinder of piston D, and piston D' having moved down far enough to connect, by means of bleederpassage b4, that end of the cylinder above D' with the space between pistons D and D', and the pressure above piston D having access, by bleeder-passage b2, to the upper end of the cylinder of piston D', the pressures in the upper ends of these cylinders in the space between their pistons D and D' and about the neck of piston D almost instantly equalize, so that spring d can raise piston D, thereby opening the supply-passage through inlet B.

lIt is obvious that nay-invention is applicable generally to regulating or varying the pressure in the outlet, as will be clear without description to all skilled in the art.

The operation will be fully understood without further description, except that it is my opinion that after the pressure under the diaphragm attains the desired amount the motion of both pistons is under usual conditions in the use of my reducing-valve slight and almost incessant-that is, each of the pistons vibrates endwise many times per minute and for small distancesfor the effective pressures tending to move the pistons endwise are in practice constantly changing within small limits, as the pressure in the outlet varies slightly; but of course if the supply of steam from the outlet be at one time slight and at another time large the motions of the two pistons will Vary accordingly.

What I claim as my invention is- 1. The reducingvalveabovedescribed com prising an inlet; an outlet; a cylinder connected vwith the inlet and having a piston- Valve controlling the inlet; a second cylinder connected with the outlet and having a piston-Valve controlling the outlet; a port connecting the cylinders; a Valve controlled by a diaphragm and controlling a port through which the low pressure to be regulated has access to the cylinder next the inlet; and a spring normallyholding the inlet piston-valve clear of the inlet and clear of the port connecting the cylinders.

2. In a reducing-valve the combination of two pistons; their cylinders; an inlet opening into one of the cylinders; an outlet opening out of the other cylinder; a port connect- IOO tion after it has been moved by the inflow of ing the tWo cylinders; a spring-controlled iiuid under pressure through the port of the diaphragm acted upon on one side by the pressure to be regulated; a Valve controlled valve controlled by the diaphragm. by that diaphragm; a port controlled by that i 5 valve and leading into one end of the cylinder next the inlet; and a spring for returning the piston next the inlet to its normal posi- PATRICK E. GAIN.

Witnesses:

G. A. RooKWELL, C. B. MAYNADIER. 

